Australia's leading expert on Indonesia's legal system says convicted drug trafficker Schapelle Corby's five-year clemency deal is good news not just for her, but also for two Australian drug smugglers on death row.

The director of the Asian Law Centre at the University of Melbourne, Professor Tim Lindsey, says it appears the president is willing to be flexible.

He says Mr Yudhoyono's decision is surprising because he had previously indicated he would not exercise clemency in favour of convicted drug smugglers.

Professor Lindsey says that will provide a glimmer of hope to Australian Bali Nine drug smugglers Andrew Chan and Myuran Sukumaran, who are facing the death penalty in Indonesia.

"I think it's very significant, in particular for the Australians currently on death row, the two remaining members of the Bali Nine, Sukumaran and Chan, who will be seeking clemency from the president in order to avoid the death penalty," he said.

The president has, on many occasions, indicated he would not use his power of clemency in favour of drugs offenders. He's just done so and he's done so to a very significant degree.

"The president has, on many occasions, indicated he would not use his power of clemency in favour of drugs offenders.

"He's just done so and he's done so to a very significant degree. Five years from 20 is not a small reduction."

Indonesia's minister for the state secretriat, Sudi Silalahi, says the clemency deal is based on humanitarian grounds as well as a reciprocal arrangement with Australia, which has already returned some young Indonesians accused of crewing asylum seeker boats.

Professor Lindsey says there are a lot more Indonesians in Australian jails than Australians in Indonesian jails.

"The Indonesians are rightly concerned about the welfare of their citizens in our jails as they are of citizens of their own in other countries," he said.

"I think that any confessions by our government in relation to Indonesians in custody here is going to help negotiations in relation to our people in their prisons."

But he says continuing calls in Australia for the execution of Bali bomber Umar Patek could be a significant hurdle to the chance of more deals.

"As an abolitionist country, we want Indonesia not to exercise the death penalty in relation to our citizens, so we can hardly go around calling for it to exercise the death penalty in relation to its own citizens," he said.

"We have to be consistent on this.

"And I think that, to politicians, for Umar Patek to receive the death penalty, no matter how heinous his crimes, is contrary to national policy and would only endanger Australians on death row."